Manufacturing Methods for the Production of Field Effect Electron Emitters from Oxide-Metal Composites.
Final technical rept. 16 May 75-15 Nov 77,
GEORGIA INST OF TECH ATLANTA
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This report describes the procedures for the routine growth and fabrication of production quantities of field emitters from oxide-metal composites grown by unidirectional solidification. The composites consist of 1,000,000 to 50,000,000 ordered 0.5 micrometer diameter tungsten fibers per sq. cm aligned in an UO2 matrix. Urania powders from four vendors were characterized according to initial ou ratio, sinterability, and applicability for growth of well ordered composites. Parameters controlling successful growth of the UO2-W composites were investigated and optimized for solidifying ingots weighing up to 500 grams. To fabricate these materials into cathodes, machining, brazing, and chemical etching techniques were developed with compatible thermal expansion characteristics being a major consideration. Lastly, the field emission performance of a variety of prototype emitters were tested and current densities of over 1 Asq. cm were obtained. Mechanisms leading to pin failures during emission were analyzed. Author
- Electrical and Electronic Equipment
- Solid State Physics